Stable structure



Jan. 7, 1969 c. R. BISHOP 3,420,066

STABLE STRUCTURE Filed Sept. 18, 1967' Sheet of 2 I l I l- 22 I l l I 5 a 27 53 i i a i s I 'l l 1 4- Z5 CAMPLES gem/0e 0505,4550 5y MII/P/EL (ZR/SHOP, nature/x lrrewaf bill/5N roe Jan. 1, 1969 v c. R. 8.5% 3, 6

STABLE STRUCTURE Filed Sept. 18, 1967 1 Sheet of 2 me/v fax? Cf/A/PLES xa BISHOP} 05054650 5r MU/P/EL 0. 5/67/01, EXECUTE/X ,lrrae/ved' United States Patent Office 3,420,066 Patented Jan. 7, 1969 3,420,066 STABLE STRUEIJ'IHREf G d G arles Richard Bisho decease a e ar en rov e, Calif., by Muriel Ja iiet Bishop, executrix, 10342 Hill Road, Garden Grove, Calif. 92640 Continuation-impart of application Ser. No. 418,203, Dec. 14, 1964. This application Sept. 18, 1967, Ser. No. 668,993 US. Cl. 6146.5 7 Claims Int. Cl. E02b 17/00 ABSTRACT OF THE DISCLOSURE A support structure which is designed to accommodate itself to unevenness in the surface of terrain or continuing undulations in the surface of a body of water upon which it is supported, which includes four elongated corner posts that are arranged at the respective corners of a rectangle and are intended to remain in vertically aligned positions at all times, a rigid housing which at all times is aligned precisely perpendicular to the posts and hence normally in a horizontal plane, and a dual flexible frame for supporting the rigid housing from the posts, one portion of the flexible frame being attached at the upper ends of the .posts and the other portion being attached at the lower ends of the posts, and the dual flexible frame being pivotally joined both to the posts and to the rigid housing in such manner that the elevation of the rigid housing is intermediate to the elevation of the lowest and highest posts and is determined in part by the elevation of each post.

BACKGROUND OF THE INVENTION This application is a continuation-in-part of my copending application Ser. No. 418,203 filed Dec. 14, 1964. The present invention relates to a stable structure which includes a rigid housing, four vertically movable support members, and means coupling the rigid housing to the support members so as to provide maximum stabilized support for the rigid housing.

In many applications it is necessary that a rigid structure be transported over uneven roadway, or installed In a level position on uneven terrain, or supported in a horizontal position upon the undulating surface of a body of water. In any one of these situations it is advantageous to utilize a supporting structure which includes a rigid housing adapted to contain or support rwhatever operative mechanism is required for the particular purpose at hand, and in addition thereto, a flexible support means for supporting the housing and accommodating itself to unevenness in the supporting terrain or body of water. In the typical situation a three-dimensional problem is presented, in which the rigid housing and associated structure to be supported has substantial vertical height as well as substantial breadth in the horizontal plane, and in which the associated flexible support means may also have substantial vertical height as well as breadth.

The primary object of the present invention is to provide a stable structure having a substantial vertical height, which is able to adapt itself to unevenness in the supporting terrain or water surface without substantial interference to the stability of the structure.

A further object of the invention is to provide such a stable structure which is specifically designed for supporting an offshore well drilling rig on the surface of an ocean body.

SUMMARY OF INVENTION The present invention includes the combination of four elongated corner posts which remain vertically aligned at all times, a rigid housing having a substantial height, and upper and lower flexible frames each of which is interconnected between the rigid housing and the four corner posts so as to provide support for the rigid housing in such manner that up and down movements of each individual corner post are only partially imparted to the rigid housing.

The objects and advantages of the invention will be more fully apparent from the following description considered in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a perspective 'view of a presently preferred form of the invention;

FIGURE 2 is a fragmentary plan view of one corner of the structure of FIGURE 1;

FIGURE 3 is a fragmentary cross-sectional view taken on the line 3-3 of FIGURE 1;

FIGURE 4 is a vertical elevational view, partially in cross section, of one corner of the structure of FIGURE 1 when permanently supported by a piling;

FIGURE 5 is a fragmentary cross-sectional view taken on the line 55 of FIGURE 2;

FIGURE 6 is a perspective view of one modified form of the invention;

FIGURE 7 is a fragmentary cross-sectional view taken on the line 77 of FIGURE 6; and

FIGURE 8 is a schematic illustration of another modified form of the invention.

Reference is now made to FIGURES 1 to 5 illustrating the basic embodiment of the present invention. As best seen in FIGURE 1, there are provided at the four corners of the structure respective vertically extending and vertically movable support members, which are designated as 15, 16, 17, and 18 respectively. These support members may typically be hollow float units, for supporting the entire structure upon or in the surface of a body of :water, but as previously pointed out, the invention is of course not limited to use in conjunction with water. The primary \element, or load portion of the structure, is a rigid housing 20. In the present illustrations the rigid housing 20 is essentially in the form of a square, box-like structure having open upper and lower ends. Alternatively, the rigid housing may, for example, take the form of a vertically extending open cylinder. Many other configurations of the rigid housing are possible within the scope of the present invention, and in general it is only essential that the housing have a substantial vertical dimension, and make suitable provision for attachment of four pivotal bearing supports thereto in an upper region, as well as four bearing supports in a lower region, in the manner which will be subsequently explained.

As best seen in FIGURE 1 the invention also includes an upper flexible frame 30, which in turn includes side members 31, 32, 33, and 34, and corner pieces 35, 36, 37 and 38. Corner pieces 35 to 38 are coupled to the movable support members 15 to 18, respectively, in a manner which will subsequently be described. The various side members extend generally horizontally, with the side member 31 intercoupling corner pieces 35 and 36, side member 32 intercoupling corner pieces 36 and 37, side member 33 intercoupling corner pieces 37 and 38, and side member 34 intercoupling corner pieces 38 and 35. Each of the side members is pivotally coupled at its longitudinal center to a corresponding separate point on the rigid housing 20, so as to pivot about a horizontal axis relative to the rigid housing 20. In FIGURE 1 the upper frame portion of the rigid housing 20, around its entire periphery, is designated 27. The longitudinal center of side member 31 of the upper flexible frame 30 is pivotally coupled to one of the members 27 by a pivotal connection means 210; the longitudinal center of side member 32 is pivotally connected to another of the members 27 by pivotal connection means 22a; the side member 33 is pivotally connected to still another member 27 by the pivotal connection means 23a; and the side member 34 is connected to, the remaining member 27 by pivotal connection means 24a.

Reference is now made to FIGURE 3 illustrating the typical construction of the pivotal connection means. As shown in FIGURE 3 the pivotal connection means 24a: is arranged as follows. The side member 34 is tubular in form, and has laterally opposed openings made therein which receive a transversely extending tube stub 51, which is of substantially lesser diameter than the tube 34. The associated member 27 is likewise tubular in form and has lateral openings which receive a smaller tube stub 52. A pin 53 has an enlarged central portion and has two extending end portions which are cut to a smaller diameter, one of the end portions being received in the tube stub 51 and the other being received in the tube stub 52. The projecting extremities of the pin 53 are threaded, and are secured by nuts 53a and 531), respectively. It is evident that with this structure the side member or side tube 34 is able to rotate, relative to member 27 of the rigid frame, about a horizontal axis which coincides with the longitudinal axis of the pin 53. It will also be seen that the nuts 53a and 53b serve as fastening means, to retain the side members in position adjacent the rigid housing 20.

Each corner piece such as 35, as illustrated in FIGURE 2, includes a pair of mutually perpendicular tube sections, each having a fixed rod such as 60 extending from the end thereof. The rods 60 are received in the ends of the side tubes 31 and 34, respectively. As the support members 15 to 18 move up and down relative to each other and to the rigid housing, there is some extension and contraction of the sides of the flexible frame 30, with the result that the rods 60 not only rotate within the ends of the side tubes, but also to some limited extent slide longitudinally within those tubes.

In accordance with the present invention the support members 15 to 18 are adapted to move vertically upward or dowvnward without changing their vertical orientation. Accordingly, hinged connection means are utilized in conjunction with each of the aforesaid support members for fastening the associated corner piece thereto. Thus the top of the support member or float 15 has a parallel pair of cars 55a, 55b welded thereto, with suitable openings through which the ends of a pivot pin 57 pass. Each of these openings is a slot 90 which is elongated in the vertical direction so as to permit a limited degree of pivotal or rocking movement of the pin 57 in a vertical plane. A short tube 56 is received on the central portion of the pivot pin 57, and is welded to the mutually perpendicular tubes of the corner piece 35. Tube 56 may properly be considered as a part of the hinged fastening means, and it may also properly be considered as a part of the corner piece itself. The result of this arrangement is that the corner piece 35, and consequently the ends of the respectively associated side members 31 and 34 of the upper flexible frame 30, are able to rotate relative to the float member 15 about a horizontal axis (the longitudinal axis of the pivot pin 57) which extends at an angle of 45 to the ends of the side members. Depending upon the relative vertical positions of floats 16 and 18 this rotational movement may also be accompanied by a rocking movementof the pivot pin 57 in the vertical plane.

The embodiment of FIGURES 1 to 5 also includes a lower flexible frame 40, which is constructed in the same manner as the upper flexible frame 30. The lower flexible frame includes side members 41, 42, 43 and 44, 'which are attached to the rigid housing 20 at corresponding separate points thereon, by means of pivotal connections 21b, 22b, 23b and 24b, respectively. The lower flexible frame 40 also includes corner pieces, not clearly shown in the drawings, but which are identical to the corner pieces of the upper flexible frame. Each of the corner pieces is in turn coupled to the associated one of the float members by means of a hinged fastening, like that shown in FIGURE 2.

It will therefore be seen that any two of the float members, together with the two side members of the upper and lower flexible frames which intercoupled them, form a parallelogram. Since the parallelogram is suspended at its two horizontal midpoints, the rigid frame 20 and the two float members are able to move vertically up or down relative to each other without changing. the direction of orientation of any of them. It is true, however, that if the average elevation of the float members on one side of the structure becomes higher or lower than the average elevation of those on the other side of the structure, then the rigid housing 20 will become inclined at somewhat at an angle to correspond accordingly.

In the preferred use of the invention as a stable latform for supporting a well drilling rig on the undulating surface of a body of water, such as an ocean body, certain additional aspects of the invention become significant. As shown in FIGURE 4, it may be desirable to drive vertical pilings, such as the piling 65, through the hollow vertical centres of corresponding ones of the float members. The pilings are of course driven into the ocean floor, and serve to stabilize the structure against horizontal movement in response to the undulations of the water surface. The various float units then reciprocate up and down, in vertical motion, but without substantially affecting the elevation of the rigid housing 20. When a vertical piling is driven through each of the float members the effect of this arrangement is to prevent any significant tilting action of the rigid housing 20. It will of course be readily apparent that the rigid housing 20, either in the form illustrated or in some other suitable fonm as previously referred to, provides the base structure upon which the well drilling apparatus and associated equipment are supported.

In FIGURE 4 the ocean body is designated as 70. In some instances it may be desirable to stabilize the float units vertically as well as horizontally, after the drilling rig has been placed in its operative position. In that event a collar such as 66 may be permanently attached to the upper end of each float unit, and a pin such as 67 may be passed through suitable openings in the collar 66 and the associated piling so as to provide vertical stabilization of the float unit.

Another significant feature of the invention is illustrated in FIGURES 6 and 7. The undulations or waves in the surface of an ocean body are generally characterized, at any given point of time, by substantially constant horizontal spacing. That is, the distance between the first and second wave crests is substantially equal to the distance between the second and third wave crests, and the distance between the first and second troughs is substantially equal to the distance between the second and third troughs. The relationship of the wave spacing to the horizontal dimensions of the structure of the present invention, and more particularly, to the float units thereof, is significant. In the illustration of FIGURE 1 a first diagonally opposite pair of float units 15 and 17 are shown as being supported in the tops of two adjacent wave crests. At the same time the other diagonally opposite pair of float units 16 and 18 are shown as being supported in the trough that lies between the two wave crests. Assuming that the depth of the trough below the average water surface height is the same as the height of the crests above that average surface height, it will be readily apparent that the elevation of rigid housing 20 will be the same as if the water surface were absolutely smooth. Furthermore, in this type of situation, the horizontal movement of the wave structure past the mechanism of the present invention causes upward and downward movements of the various ones of the float unitswhich, in an ideal situation, would produce no vertical displacement whatsoever of the rigid housing 20. Furthermore, there would, ideally, be no force tending to raise or lower the rigid housing 20, and no force tending to twist it away from its true vertical alignment. Thus, theoretically at least, the rigid housing 20 provides a perfectly satisfactory base from which to drill a well through the ocean floor.

Since the horizontal separation between wave crests and wave troughs varies as a function of time, due to changes in the weather and the position of the moon and other factors, it necessarily follows that a horizontal separation of the float units which would match the spacing between two wave crests at one point of time would not necessarily do so at some other point of time. The apparatus of FIG- URES 6 and 7 is therefore provided in order to adjust, or tune, the float positions to the existing wave separation. Thus, as shown in FIGURES 6 and 7, there is used in lieu of the hinged fastening arrangement of FIGURE 2, an arrangement which provides a hinged coupling between the upper and lower ends of a float, but at the same time permits horizontal adjustment of the position of the float relative to the associated corners of the upper and lower flexible frames.

As shown in FIGURE 6 a rigid rectangular frame 75 is firmly attached to each of the corner pieces of the upper and lower flexible frames. Each of the elongated rigid frames 75 has guideways 76a and 76b formed in the parallel legs thereof. A threaded shaft 77 has one end pivotally attached by means of a pivotal connection 78 to the outer vertical side of the float member 15, while its other end is received by a drive mechanism 79 carried on the outer extremity of the rigid frame 75. The drive mechanism 79 is powered by a motor 80, which is also carried on the outer extremity of frame 75. The float 15, in this configuration, carries a pivot pin 57a having extended ends which engage the guideways 76a and 76b. Pivot pin 57a is arranged to pivot to some extent in a vertical plane, relative either to the frame 75 or to the float 15, by means not specifically shown. Thus by simultaneously energizing the motors 80 associated with both the upper and lower ones of the frame 75, the float unit 15 may be moved inwardly or outwardly relative to the flexible frames 30 and 40 as well as to the rigid housing 20. In the illustration of FIGURES 6 and 7 the rigid frames 75 extend horizontally outwardly from the corner pieces of the flexible frames, in an angular direction perpendicular to the axis of the pins 57a, so that the hinged action of the apparatus occurs in the same manner as before. The rotatable coupling between each corner piece 35 and the associated side members of its flexible vframe 30 or 40, while not specifically shown in FIGURE 6, are the same as in the embodiment of FIGURES 1 to 5.

The apparatus of FIGURES 6 and 7 may be utilized for tuning the float units, by moving them horizontally inwardly or outwardly relative to the rigid housing 20, so as to better accommodate them to the then existing horizontal spacing of the waves. Through the use of this mechanism the stability of the structure may be maintained even though the character of the waves or undulations of the ocean surface varies from time to time, as it necessarily does Reference is-jr'iow made to FIGURE 8 illustrating another modified form of the invention. As shown in FIG- URE 8, there may be used in lieu of the apparatus of FIGURES 6 and 7, either one or a pair of float units such as 15a and 15b associated with each corner piece 35, supported by a different arrangement. More specifically, each float unit may be supported from the adjacent corner pieces of the upper and lower fllexible frames by means of a pair of support arms 85 attached to the upper and lower ends of the float. Means, not specifically shown, are provided for rotating the arms 85 in the horizontal plane relative to the corner pieces 35. Means, not specifically shown, are also provided for rotating the float unit in the horizontal plane relative to the attached ends of its pair of support arms 85. As a result of this arrangement, as shown by the alternate positions of the float units as illustrated in dotted lines, it becomes possible to move the float units inwardly and outwardly relative to the rigid housing 20, along curved paths. The advantage of the curved path is that it gives a greater flexibility in the adjustment of the structure to adapt to the then existing nature of the ocean waves.

While the invention has herein been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

What is claimed is:

1. In a body of water having an undulating surface, a stable structure comprising, in combination:

four floats disposed in the horizontal plane so as to form substantially the four corners of a square, each of said floats having a substantial vertical height;

a substantially horizontally disposed upper flexible frame intercoupling upper portions of said floats;

a substantailly horizontally disposed lower flexible frame intercoupling lower portions of said floats, each of said flexible frames including four corner pieces disposed adjacent respective ones of said floats, and four side members each of which intercouples a respectively adjacent pair of said corner pieces, one of each of said corner pieces and side members having a cylindrical opening and the other of each of said corner pieces and side members having a cylindrical portion received in said opening so that the ends of said side members are rotatable about the longitudinal axes of said side members relative to said corner pieces;

a rigid housing disposed within said flexible frames and having substantial vertical height;

means pivotally connecting the longitudinal center of each of said side members to corresponding separate points on said rigid housing whereby said corner pieces of both of said flexible frames are permitted to move up and down relative to said rigid housing and to each other;

and hinged connection means connecting each of said corner pieces to the respectively associated float whereby said corner piece may rotate relative to said float about an axis which extends at an angle of 45 relative to the respectively associated side members, and may concurrently pivot in a vertical plane relative to the associated float.

2. A stable water-borne structure as claimed in claim 1 wherein said side members are of tubular form.

3. A stable water-borne structure as claimed in claim 1 wherein each of said corner pieces includes a pair of tubular members disposed in mutually perpendicular relationship.

4. A stable water-borne structure as claimed in claim 1 wherein each of said floats has a vertically extending central opening formed therein, and which further includes four pilings occupying respective ones of said openings.

5. A stable water-borne structure as claimed in claim 1 which additionally includes adjustment means cooperatively associated with at least one of said floats and its respectively associated upper and lower hinged fastening means, said adjustment means being operable for varying the horizontal position of said float relative to the respectively associated corner pieces of both of said flexible frames.

6. Apparatus as claimed in claim 5 wherein said adjustment means is adapted to move said float inwardly or outwardly, in a straight line, relative to said rigid housing.

7. Apparatus as claimed in claim 5 wherein said adjust- 7 8 ment means is adapted to move said float along a curved 3,151,594 10/1964 Collipp 61--46.5 X path relative to said rigid housing, so as to provide a 3,273,526 9/1966 Glosten 61-465 X selected position of said float.

References Cited 5 JACOB SHAPIRO, Primary Examiner.

UNITED STATES PATENTS 2,895,300 7/1959 Hayward 6146.5 3,150,628 9/1964 Brinkmann et al. 61--46.5 X 61-63; 114-.5; 9-8; 248-188.3 

